Portable mobile phones typically have two housings rotatably joined by a type of hinge that allows the housings to fold upon one another. Many such foldable mobile phones have most of the electronics in one housing, called the main housing, and fewer electronics in the other housing, called the cover. Other such foldable mobile phones have all the electronics in the main housing, with the cover serving only to cover a keypad and a display of the main housing. The main housing and the cover are connected together by a hinge mechanism. Generally, the opening or closing of most covers is achieved by means of cams and a spring of the hinge mechanism.
FIG. 8 illustrates a hinge assembly used in a conventional type of foldable mobile phone. The foldable mobile phone 100 includes a main housing 102 and a cover 104. The hinge assembly includes two cams 200, 202, a spring 204, and a pair of posts 106 contained in the main housing 102. A channel 1042 is defined through an end of the cover 104. The cam 202, the spring 204, and the cam 200 are fixed in the channel 1042 in that order. The cams 200, 202 protrude out from the channel 1042 and engage with the posts 106. When the cover 104 is rotated, the cams 200, 202 rotate along with the cover 104, and stop the cover 104 in a position where it maintains an angle of 180° relative to the main housing 102.
However, the hinge assembly includes a variety of individual pieces that must be installed within the foldable mobile phone 100 when the foldable mobile phone 100 is assembled. This does not meet the growing trend for foldable mobile phone manufacturers to use integrated one-piece hinge assemblies that can be quickly and easily press-fitted into foldable mobile phone sub-assemblies during manufacturing. Manufacturing costs associated with non-integrated hinge assemblies are higher than those associated with one-piece hinge assemblies.
What is needed, therefore, is a hinge mechanism which is modularized, easy to install into a foldable electronic device, and low in cost.